The present invention relates generally to cable ties, and more specifically to a cable tie which includes a Christmas tree fastener.
Cable ties are well known in the art and are used in a variety of applications such as securing a cable to a mounting structure.
When used for securing a cable to a mounting structure, cable ties often include a fastener, an elongated strap and a locking head integrally connected to one end of the strap. In use, the free end of the strap is inserted into a channel in the locking head to form a loop around the cable, wherein increased insertion of the free end of the strap into the locking head decreases the size of the loop. The cable tie is locked into place around the cable by a locking tang or pawl located within the locking head which engages teeth or cross-bars formed on the strap. The fastener is then used to secure the cable to the mounting surface.
One type of fastener used in cable ties is sized and shaped to be inserted through an aperture in the mounting surface.
In U.S. Pat. No. 5,333,822 to James C. Benoit and Charles L. Deschenes, which patent is incorporated herein by reference, there is disclosed a locator tie for attaching an element, such as a bundle of electrical wires, to a thin wall having an aperture. The locator tie is made of plastic and comprises a cable tie capable of surrounding and engaging the element and a fastener integrally formed with the cable tie, the fastener being adapted so that it can be easily inserted into the aperture but removed from the aperture only with great difficulty. The fastener includes an arrowhead mounted on a support and surrounded by a spring-biased basket. The cable tie includes a strap having a head portion which is on one side of the fastener and a tail portion which is on the other side of the fastener. The head portion includes an engagement head and the tail portion includes an engagement surface, which, when fed through the engagement head is locked in the engagement head and cannot thereafter be extracted. The strap also includes a pair of holding blocks, one on the head portion of the strap and the other on the tail portion of the strap for engaging a corrugated socket which surrounds the bundle of wire.
It is also well known in the art for cable ties to comprise a fastener generally in the shape of a pine-tree or a Christmas tree which is sized and shaped to be inserted through an aperture in a mounting surface. These fasteners are widely used in the art due to the low insertion force required to insert the fastener through the aperture of the mounting surface and due to the high extraction force required to extract the fastener from the aperture of the mounting surface.
For example, in U.S. Pat. No. 4,342,438 to R. Speedie there is disclosed a unitary plastic material cable strap fastener having a flange with a plug member on one side for engaging in a hole in a panel to hold the fastener in position. The plug includes a stem with a head at its end and rows of radial wings arranged along its length. A stud extends from the opposite side of the flange coaxial with the plug. A flexible strap member is attached to the flange by a bifurcated end having a pair of legs formed by an opening in the strap end. The strap extends from the flange in the same direction as the stud with the stud extending into the opening with the legs straddling the stud. The strap is provided with a series of stud receiving openings for engaging the stud when the strap is formed into a loop. The flexible legs of the strap permit the strap to be rotated or folded relative to the longitudinal axis of the plug and stud so that it extends perpendicular thereto to permit the stud receiving openings to engage the stud.
One drawback of pine-tree shaped fasteners of the type described above is that such a fastener is adapted to be inserted through apertures of a particularly narrow range. In particular, if the diameter of the aperture in the mounting surface is slightly smaller than the diameter of the fastener, either the user will not be able to insert the fastener through the aperture or the user will require an extremely high insertion force be able to insert the fastener through the aperture, which is undesirable.